JP2813497B2 - Scroll type fluid machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type fluid machine.

[0002]

2. Description of the Related Art An example of a conventional scroll compressor is shown in FIG.
Describing a longitudinal sectional view, the inside of the sealed housing 8 is partitioned into a high-pressure side 44 and a low-pressure side 45 by the discharge cover 31. Inside the low-pressure side 45, a scroll-type compression mechanism C is disposed at an upper part thereof, and an electric motor M is disposed at a lower part thereof. The electric motor M includes a rotor Ma and a stator Mb. The rotor Ma is fixed to the rotating shaft 5, and the stator Mb is fixed by press-fitting the sealed housing 8. The scroll-type compression mechanism C has a fixed scroll 1 and an orbiting scroll 2. The fixed scroll 1 has an end plate 11 and a spiral wrap 12 erected on its inner surface.
A discharge port 13 is provided at a central portion of 1. The orbiting scroll 2 includes an end plate 21 and a spiral wrap 22 erected on the inner surface of the end plate 21, and a drive bush 54 is provided with a slewing bearing 73 in a boss 23 erected on the outer surface of the end plate 21.
The drive bush 5 is rotatably fitted through the
An eccentric pin 53 projecting from the upper end of the rotating shaft 5 is slidably fitted in a slide hole 55 formed in the rotary shaft 4. The fixed scroll 1 and the orbiting scroll 2 are eccentric to each other by a predetermined distance, and are engaged with each other at an angle of 180 degrees to form a plurality of closed spaces 24. The orbiting scroll 2 is slidably supported on a casing 6 fixed in a sealed housing 8, and allows the orbiting scroll 2 to revolve orbit between the orbiting scroll 2 and the casing 6, but prevents the orbiting scroll from rotating. A rotation prevention mechanism 3 including an Oldham link is provided. The fixed scroll 1 is supported by the casing 6 so as to be able to float via a support spring 32 disposed on the outer periphery of the end plate 11. Cylindrical flanges 15 and 16 project upward, and a cylindrical flange 39 projecting downward on the lower surface of the discharge cover 31 is sealed between the inner and outer seal members 37 therebetween. A back pressure chamber 40 surrounded by these is formed by tightly slidable fitting, and this back pressure chamber 40 is closed through a pressure guiding hole 41 formed in the end plate 11 while gas is being compressed. It communicates with the space 24. Here, the pressure guiding hole 41 is the wrap 1
2 is located at a point in contact with the inner diameter side. A high-pressure chamber 42 is formed on the inner peripheral side of the back pressure chamber (also called an intermediate pressure) 40, and a low-pressure chamber 43 is formed on the outer peripheral side. The upper end of the rotating shaft 5 is provided with an upper bearing 7 provided on a casing 6.
1 and a lower end of the lower bearing 72. In such a structure, when the electric motor M is driven, the orbiting scroll 2 is driven by the orbiting drive mechanism including the rotary shaft 5, the eccentric pin 53, the drive bush 54, the boss 23, and the like. While revolving around, a revolving orbiting motion is made on a circular orbit having the orbital turning radius as a radius. Then, gas enters the low-pressure chamber 45 through the suction pipe 82,
It is sucked into the closed space 24 via a path not shown. As the volume of the closed space 24 decreases due to the revolving orbiting motion of the orbiting scroll 2, the gas is compressed and reaches the central portion while being compressed, enters the high-pressure side 44 from the discharge port 13 through the high-pressure chamber 42, and is discharged therefrom. The pipe 83 and the check valve 84 contained therein are pushed open to be discharged to the outside. At this time, the fixed scroll 1 is pressed against the orbiting scroll 2 by the gas pressure in the high-pressure chamber 42 and the back-pressure chamber 40, thereby suppressing gas leakage from the closed space 24. When the liquid is sucked into the closed space 24, the fixed scroll 1 floats and escapes the liquid, thereby preventing the scroll-type compression mechanism from being damaged. Although the high pressure chamber 42, the back pressure chamber 40, and the low pressure chamber 43 are respectively formed on the back side of the fixed scroll 1 in the upper figure, these are formed on the back side of the orbiting scroll 2, respectively, and these chambers 42, 40, 43
The orbiting scroll 2 can be pressed against the fixed scroll 1 by a back pressure load based on the above. By the way, in a helium gas compression unit incorporating this type of scroll compressor, as shown in the system diagram of FIG. 3, low-pressure helium gas returned from a demand destination is supplied to a scroll compressor 101 via a surge bottle 105. The inhaled and compressed helium gas enters the discharge gas cooler 102 in a state containing oil, is cooled by cooling water, and then guided to an oil separator 103, where helium gas and oil are separated. The helium gas separated from the oil is supplied to a demand destination via the adsorber 104. On the other hand, the oil separated by the oil separator 103 is injected into the closed space 24 shown in FIG. 2 through the injection pipe 91 to cool the compressed gas in the closed space 24, and the scroll type compression mechanism C Sealed.

[0003]

However, in this type of scroll type compressor, part of the lubricating oil (hereinafter referred to as oil) injected into the closed space 24 through the injection pipe 91 is transferred to the closed space 24. The oil leaks due to the pressure difference from the suction chamber 16 and flows down to the oil sump 81 via the suction chamber 16. Therefore, the oil level of the oil sump 81 rises, and the electric motor M is immersed to increase the required power of the compressor. May be invited.

The present invention has been proposed in view of the above circumstances, and provides an economical scroll type fluid machine which prevents the power loss of a compression mechanism by maintaining the oil level of an oil reservoir at a set value. With the goal.

[0005]

To this end, the present invention provides a scroll type compression mechanism having a fixed scroll and an orbiting scroll housed in a hermetically sealed housing and engaging the fixed scroll with the orbiting scroll. In a scroll type compressor in which lubricating oil is injected into a closed space, a ventilation is provided for communicating an internal space of the closed housing into which suction gas is introduced and a suction chamber provided in the scroll type compression mechanism. It is characterized by having an oil passage with resistance.

[0006]

According to such a configuration, ventilation resistance is added to the gas passage between the internal space of the sealed housing and the suction chamber, and the internal space is placed in a higher pressure state than the suction chamber. Therefore, when a part of the oil injected into the closed space flows down through the suction chamber into the oil sump and the oil level rises, the oil sump is generated due to the pressure difference between the oil sump and the suction chamber in the same pressure state as the internal space. Is guided to the suction chamber through the oil passage, and is sucked into the sealed space together with the gas.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of an embodiment of the present invention. In the above figure, the same reference numerals as those in FIG.
In addition, a gas passage 85 formed in the cylindrical flange 18 is provided with a throttle 92 that partially reduces the cross section of the gas passage 85, thereby increasing the pressure resistance of the gas passing through the gas passage 85 and increasing the internal space. 37 is placed in a higher pressure state than the suction chamber 16. An oil pipe 93 connecting the suction chamber 16 and the oil sump 81 is provided in the closed housing 8.
The lower end of the oil pipe 93 is connected to a predetermined oil level position of the oil sump 81. Here, the oil pipe 93 can be provided inside the closed housing 8. The pressure resistance of the gas added by the throttle 92 is set so as to exceed the position head of the oil filled in the oil pipe 93. Other structures are the same as those of the conventional structure shown in FIG. 2, and corresponding members are denoted by the same reference numerals. Thus, during operation of the compressor, the internal space 37 of the closed housing 8 is placed in a higher pressure state than the suction chamber 16 by the throttle 92. For this reason, part of the oil injected into the closed space 24 from the injection pipe 91 leaks and the suction chamber 16
When the oil level rises after flowing down to the oil sump 81 via
Due to the pressure difference between the oil sump 81 in the same pressure state as the internal space 37 and the suction chamber 16, the oil in the oil sump 81 becomes
Through the suction chamber 16, and together with the gas, the closed space 2.
It is inhaled into 4. Thereby, the oil level of the oil sump 81 is maintained at the predetermined position.

[0008]

According to such a structure, ventilation resistance is added to the gas passage between the internal space of the sealed housing and the suction chamber, and the internal space is placed in a higher pressure state than the suction chamber. Therefore, when a part of the oil injected into the closed space flows down through the suction chamber into the oil sump and the oil level rises, the oil sump is generated due to the pressure difference between the oil sump and the suction chamber in the same pressure state as the internal space. Is guided to the suction chamber through the oil passage, so that the oil level of the oil reservoir can be maintained at a predetermined position, and an increase in required power due to the rise of the oil level can be prevented.

In short, according to the present invention, a scroll-type compression mechanism having a fixed scroll and an orbiting scroll is housed in a closed housing, and the inside of an enclosed space formed by meshing the fixed scroll and the orbiting scroll. In a scroll type compressor configured to inject lubricating oil, an oil passage with a ventilation resistance communicating an internal space of the closed housing into which suction gas is introduced and a suction chamber provided in the scroll type compression mechanism is provided. Since the present invention provides an economical scroll-type fluid machine that prevents the power loss of the compression mechanism by keeping the oil level of the oil reservoir at a set value, the present invention is extremely useful in industry.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a scroll compressor showing one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a known scroll compressor.

FIG. 3 is a system diagram showing a known helium gas compression unit having the scroll compressor of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed scroll 2 Orbiting scroll 3 Rotation prevention mechanism 5 Rotation shaft 6 Frame 8 Sealed housing 9 Bolt 11 End plate 12 Lap 13 Discharge port 14 Discharge muffler 16 Suction chamber 17 Discharge valve 18 Flange 22 Lapp 23 Boss 24 Sealed space 25 Drive bush 37 Internal space 53 Eccentric pin 71 Upper bearing 72 Lower bearing 73 Slewing bearing 74 Thrust bearing 81 Oil reservoir 82 Gas suction chamber 85 Gas passage 91 Injection pipe 92 Throttle 93 Oil pipe

Claims (1)

(57) [Claims] 1. A scroll type compression mechanism having a fixed scroll and an orbiting scroll is housed in a sealed housing, and lubricating oil is injected into a sealed space formed by meshing the fixed scroll and the orbiting scroll. A scroll-type fluid machine, wherein a gas oil passage with ventilation resistance communicates an internal space of the closed housing into which suction gas is introduced and a suction chamber provided in the scroll compression mechanism; A scroll-type fluid machine comprising an oil reservoir connecting the suction chamber and the suction chamber.